1. Field of the Invention
The present invention relates to a rubber mount device of a vehicular engine and, more particularly, to a dust seal structure for a rubber mount device, which has an outer cylinder portion formed in either one of a vehicle body and an engine. An inner cylinder portion is fixed with a bolt to a support portion formed in either one of the engine and a vehicle body. The inner and outer cylinders are fitted to each other via a rubber cushion.
2. Description of Background Art
In the rubber mount device described above, water, pebbles or mud may stick to or deposit on a recess which is defined by the axially outer end faces of the rubber cushion and the inner and outer cylinder portions. Thus, the rubber mount device cannot effectively perform its inherent damping function and also detracts from the durability of the device. In order to solve these problems, there already exists a proposal (as disclosed in Japanese Utility Model Registration No. 25451/1991, for example), in which a flexible cover member for covering the outer end faces of the rubber cushion is interposed between the inner and outer cylinder portions.
In Japanese Utility Model Registration No. 25451/1991, the elastic cover member is made of a relatively soft material so that it may be smoothly deformed according to the elastic deformation of the rubber cushion thereby to seal the inner and outer cylinder portions. As a result, the cover member may be largely deformed to permit water or mud to be received into the aforementioned recess when it is directly subjected to a high water pressure such as the pressure of washing water injected under a high pressure from a nozzle.
In Japanese Utility Model Registration No. 25451/1991, the device includes a cover member which is formed to have a drain port in its bottom portion so that the breached water can be discharged. However, even with this drain port, complete removal of the water or mud is difficult once it has entered into the cover member. Furthermore, fine dust or the like may enter the cover member through the drain port.